Composition for coating cement.



' tions forCoating Cement, of which the fol- I E-"Di- ST TE PAfTEnr onnioa.

cnswron LiiIs. or. rnuionnzonr, NEW YORK, assrenon 'ro ELLIS-FOSTER comrnm r; A. CORPORATION or NEW JERSEY v kconrrosrrionron. coA'rIirG CEMENT.

No Drawing.

E Lrs, a citimont, in-'the county of Vest-Chester and State'of New York, have invented certain new and useful Improvements in ComposiloWing is -a specification.

This invention relates to compositions for coating cementyand t comprises a process. ,of' coating concrete wherein the free alkali of thesurface of such co'r'icrete is preliminarily neutralized by and combined with an acid deriyed from a drying oi l';' and it also comprises a composition for this purpose containing free fatty acids derived from drying oils; all as more fully hereinafter set forth and as claimed.

' Ordinary Portland cementcontains a considerable quantity of free alkali in the form of lime, potash and soda. Other calcareous cements also have this alkaline nature. It

' is consequently difficult to paint surfaces of concrete or, calcareous'cement with ordinary oil paints forthe reason that the free alkali present saponifies the glycerids of. the

' definite length of time Without scaling and cracking o In order to overcome the difiiculties at.-

oil Vehicle used, at once destroying such oilvehicle an d'setting free glycerin. This glycerin being substantially insoluble in the oil remains in the coating as such,.making it porous and hydroscopic. Such o11 paints therefore do not adhere well nor do they remainon the painted surface for .an intendant on the painting ofconcrete surfaces,

various preliminary. washes have been used thereon without very satisfactory results. For. instance the concrete surface 1s sometimes treated with a preliminary, wash of dilute hydrochloric acid for the purpose of removing thefree' lime and other alkali. "This, however, has a number of disadvantages since it destroys the'bonding of the cement,"thereb.y weakening the surface layer and causing scaling or chipping-of the cement and aggregate. Other strong acids,

such as oxalic acid have also been tried with out satlsfactory results. Washes of 'various metallic salts, such as sulfate of zinc, alum,

and the; like, have also been tried, but these do not provefsatisfactoryin use because of double decomposition with the com )onents of the cement, destroying the hon ing of Specification of Letters Patent. Patented Sept, 29, 1914 Application medna 24, 1969. Serial m ma;

the cement and forming loose and pulverulent substances. carbonate have becn'trled for the purpose of converting the lime into "calcium carbonate, and though these solutions are fairly satisfactory yet they are expensive and the incident manipulation is also expensive.

Solutions of ammonium-- I' urthcrmore, solutions of,a1nmon1u1n car-' bonate and of the other'bo'dies stated leave the surface of the concreteina moist'con ditionso that it must be dried before a paint-coating can be applied. This requires with .a composition which will at once form a varnish coating thereon and neutralize theconsiderable time and consequently delays superficial alkalinity of the concrete by corn- A vbining therewith without production" of crumbling substancesor the disintegration, of the bonding cement in such surface. For this purpose .the concrete surface-is first treated with a wash comprising the free fatty acids of the 'clrying'oils, such as linoleic acid from linseed oil. Linoleic' acid though capable. of neutralizing fthe alkalinity of lime, potash and soda, is not .sufliciently strong to destroythe set cement. Set cement. containsconsiderable lime in its body and.

it is desirable not to use an acid. Strong enough to affect such body. Linoleic.acid

will combine with the alkali in thesurface of the concrete without penetrating farther and destroying the lime in the bondingcement I body, therein 'difi'ering' from the strong \x 'ater-sol'uble acids, such as hydrochloric and oxalic. 'In so combining with the surface lime of a granule of set cement it forms a good 'celne-ntin body calcium linoleate which keys direct? ule. The film thus forme upon the sur-- .95 to such granface *gf the granule, unites directly and" readily with any, ordinary oil arnish being like in nature thereto. lVith-a concrete sur'-,'

face treated with .linoleic' acid andithenfl painted with an ordinary 'oil paint-the lino-j. v leate of'lime maybe said to be 'alinking, 3

member between the concrete andfthebody of the paint.

WVhile the fatty aeids of the drying oils than linseed oil may be employed, in practice I prefer to use the fatty'acid ofl in seed oil. This' fattyacidmay usefullyj-be; incorporated with more or lessjoflthe'oil 30 stated, it is better adapted; for treating con- 4 from which itwas derived", or, with another 3 which have been coated with calcium linodryingoil., For example, I in painting a l leate'pi'oduced in the described action.

concrete structure I find it useful to prime thQsurface preliminarily. with a compositioh consisting of 1 part of the free fatty acidsderived from linseed'oil, 1' part of linseed oil-itself and 1 part of Chinese .wood or tungoil. A composition of this character is sufiicientlyacid to neutralize all the alkalinity likely to occur in ordinary good giiality concrete while it'contains sufiicient composition neutralize the free alkali,

ving oil to act as'varnish coating. In

use, the free li-noleic andother acids in the Iwhether lime, potash, =or soda, forming the corresponding varnish like lineleate while the drying oil adheres to the treated surface, these combinations of linoleic acid with limeand the like have drying properties similar to those of linseed oil. Any excess of free fatty acid over and above that required to combine with the superficial alkaliremains dissolved in the drying oil vehicle without materially injuring its set ting'qualities. Similar results may be obtained by treating the surface with a primer consisting of 1 part of the free fatty acid from linseed oil and 1 part-of linseed oil.

- Since" this composition contains a greater proportion of free acid than that just -crete containing a large proportion of free' alkali.- Gum thus, or crude -gum turpentine may be admixed with either of the compositions stated. The resinic acids of the gum thus, though -not "so eflicient per se,.have similar neutralizing effect in connection with linoleic acid on superficial alkalinity. A good composition for the present purposes comprising gum thus and of quite acid nature may be made by mixing .1 part of free fatty acid from linseed oil with. 1 part of Wood oil and with '1 part of gum thus. These primary coatings are applied tothe surface of? the dry concrete as a thin coating or wash, and after drying, ordinary :paint may be applied to the primed surface without danger of action on the pai'n't coating. The primary coating acts to separate the concrete from the paint P Pe v The compounds formed with lime by the fatty acid from linseed oil are insoluble in water and have drying and cementing properties.- The free fatty acid containing no glycerin, inthe formation of'calcium lino- 'leateno glycerin is set free and the primer coating does not develop hygroscopic prop- T glycerids either of the primer coatingor of linseed or other unsaponified drying oils subsequently applied. Ordinary paints adhere well to particles of cement or concrete The free fatty acids required for making the primer coating under the present invention can be produced by saponifying lin seed oil or other drying oil by protracted boiling with a solution of caustic soda, and then adding sulfuric acid until the solution is faintly acid, or untilthe total alkali of the saponified mass has been converted into sodium sulfate. The composition is warmed for a time until the free fatty acid separates as a clear oil and this is then drawn off, .leaving the glycerin .1n the aqueous layer.

The linseed oil fatty acid may then be dried by means of the usual drying agents or it maybe heated gradually up to 220 F. to remove moisture. It is then ready to be mixed with the other oils if these oils are tains a third or so of free-fatty acid is, as a' rule, sufiiciently acid for the present purposes. The action of drierssuch as manganose borate or lead oxidon these compositions in accelerating drying is also more pronounced when linseed oil or other oil. is present in addition to free linoleicacid.

. The compositions above mentioned as priming materials may also be used directly as paints for concrete by the incorporation of suitable pigments, furnishing the whole body of the coating in lieu being used merely as a primer. Ordinary zinc oxid and white lead being of a highly basic character are not so well adapted for introduction into the oily composition containing a large propor-v tion of free fatty acids as are the more inert pigments such as zinc sulfid, lithopone, barytes, whiting. gypsum, silex, magnesium silicate and the like, and I therefore prefer to employ the inert pigments in preference to those of a basic character. Suitable coloring materials may of course be added to the cement paint formed by the addition of the above-mentioned filling. or extending materials, care being used to select preferably those pigments which are unaffected by free fatty acid. As the compositions used under the present invention are somewhat moreexpensive than ordinary linseed oil paints, however, it is preferable ,to use them merely as the primer coating, using ordinary paint for the body of the coating. However, where it is desired to use these compo- 1 sun);

iromn,lfi partsilithoponef and 4 parts gyp-- v huh-lieu of rosin, which serves as a herdenmiagentfin the above mixture, resinnus material 'suclijf as gum kauri, Manila copal and the like may be employed, or the resin or reSinouSmaterial may be entirely omitted. "For quick drying compositions, the relative'amount of oil may be reduced and the proportion of the resinous bodies incr eased..- As stated, the resins contain free acidmwhichmay serye adjunctively with the tree linoleic acid; Another composition con sists of free: fatty acids from linseed oil 7 parts, 10 parts gum-kauri, 3 parts rosin, 6 parts' .benzin, 3 parts turpentine, and20 parts, sulfid;

y In 'soine'-c ases', especially in treating con-- crete' which is's'lightly damp, it is better to introduce into the paint a-small amount, of

-- water}- as thisaids the blending action.

For this purpose water maybe introduced suitably thickened by some gelatinous mate-.

rial I as 'for .GXam-ple, Irish moss 'or gelatin or emulsified in any other way into the coma position. A small amount of .linseed oil oa'p spmetimes aids in the emulsification.

" Ihis,;ma'y' be generated in thefpaint itself t me.

he use of wateri containing a small themixture' Care shouldbe taken to not usefysu'ch" a quantity'of alkali that the free fattyacid is neutralized since of course forthe present purposes a substantial amount of 'freefatty acidmust be present in the composition in order to secure a permanent and "adhering coating. The addition of water to the cement paint is beneficial also in those cases where the cement is exposed lto the suns rays or to strong heat, for under such conditions, the moisture which is always present to a greater or less extent in the concrete, exerts an expansive act on causingpaint wh ch is non-porous to blister badly. The addition of Water gives a certain amount of porosity to the paint film thereby preventing such blistering.

While'the free fatty acids of linseed oil have been described herein as best adapted tion is'used' as a priming coating. The acids from linseed 011 are, however, the best since they are permanent in storage and possess drying properties somewhat similar to those of thetlinseed oil and they blend readily with ordinary linseed oil in paint mixtures v bf carbonate of soda or caustic soda, I therebygenerating the linseed oil soap 1n 351 :which is ordinarily an advantage'as linseed oil is commonly used as the paint vehicle. As I have stated in Serial No. 638,518, entitled Composition for priming and coat- 'ing concrete, most of the resins used in the making oi'varnishes and paint oils contain a large percentage of tree resin acids and esters which are readily saponified by boiling alcoholic potash but which are slowly suponified by the alkalis of cement. Inneutralizing aconcrete surtacewith an acidcomposition which also forms a water resisting coating, the speed of neutralization has-to be considered. If the. acid component acts rapidly, neutralization is effected before the coating has set and dried. If the action of the acid component is slow, ne'utralization and reaction may go on after the set-' ting and drying of the composition, thus causing rupturing of the coating and its ultimate destruction. The resin acids differ from the fatty acids in. this respect. They are slower in neutralizing activity than the fatty acids, so slow in fact,'that a coating compound has opportunity to dry and harden before neutralizing reactions are under way and these subsequently progress to the detriment of ,thecoating. The fat-s are bodies of synthetic origin and asglycerids form Well characterized bodies. The resins are largely bodies resulting from condensation and are fluctuating in compo sition and the nature of their components is not at all well established at the present time. The copals which are so extensively used in varnish making," fluctuate very greatly. Manila copal, for example, may have an acid number of 135' and a saponification value of 185, while Angola copal will perhaps give an acid number of 6.0 and a saponification value of 135. Borneo copal will give an acid number of about 145 and a saponification' value of 180. Amber contains about 30% resin acids and nearly 70% of saponifiable esters. Common rosin has an acid number of about 140 although this varies with difierent grades. It consists largely of abietic acid or its anhydrid. Sandarac has an acid number of about 150. The uncertain composition of resins make all these figures of indifferent value and the variations in ester value and acidity to gether with the further changes taking place in the fusing or melting of the hard gums or' resins, preparatory to mixing with oils or thinners, leaves in doubt, always, the action of the resin acids and esters on the alkali of cement. The use therefore of the short oil varnishes, that is varnishes high in saponiliable' resin and low in oil for coat- .ing cement is only a makeshift at best. The fatty acids from ordinary fats, including such acids as stearic, palmitic and oleic, are

3 more rapid in their neutralizing action and are more homogeneous in composition so that their reaction Wltll cement alkali is,

more ell'ective and decisive. The same is true ofthe fatty acids of drying oils such as linseed and tnngv or soybean 011 or of the slower drying oils such as cotton seedand corn oil. The-fatty acids of the drying oils have the advantage that after neutralizing the superficial alkali, forming in the main a lime soap of a Water insoluble char- 1 acter, drying sets in and a more resistant body is produced. The lime soaps ofthe compositiona substantial proportion offree fatty acid with Which may be incorporated resin acid. 20% or so of the free fatty acid suffices. for ordinary cement or concrete.

Small proportions .of free fatty acids, say" one per cent. or thereabout, which amount,

often is found in ordinary linseed or other drying oils of commerce, does not sufiice for the purposes of the present invention. Furtherinore it is desirable as stated to have the fatty acids in a non-anhydrous condition.

What I claim is-:'

1'. In a finish coat for cement, a composition comprising at least 10% of the free fatty acid of a drying oil and acid resin and thinning and extending materials.

In a finish coating for cement a composition comprising a substantialamount of the I free fatty acids of a drying oil, an acid resin and thinning and extending materials.

In testimony whereof I have aflixed my signature in presence of two Witnesses.

CARLETON ELLIS.

Witnesses 1 Swimmer, L. Fos'rER, Framers I. NEWMAN. 

